Error Handling in C#.Net?

public static void WriteError(Exception errorMessage)
{
try
{
string strpath = "c:\\ErrorLog";
DirectoryInfo dir = new DirectoryInfo(strpath);
if (!dir.Exists)
dir.Create();

string path = strpath + "\\" + DateTime.Today.ToString("dd-MMM-yyyy") + ".txt";
if (!File.Exists(path))
{
File.Create(path).Close();
}
using (StreamWriter sw = File.AppendText(path))
{
string Line = errorMessage.StackTrace.Substring(errorMessage.StackTrace.ToString().LastIndexOf(":") + 1, errorMessage.StackTrace.ToString().Length - errorMessage.StackTrace.ToString().LastIndexOf(":") - 1);
int endind = errorMessage.StackTrace.ToString().ToLower().IndexOf("object sender");
string error = errorMessage.StackTrace.ToString().Substring(0, endind - 1);
int startind = error.LastIndexOf(".");
string Event = error.Substring(startind + 1);

string err = "Log Entry : " + DateTime.Now.ToString() + Environment.NewLine +
"Error Message : " + errorMessage.Message + Environment.NewLine +
"Event Name : " + Event + Environment.NewLine +
"Line No : " + Line + Environment.NewLine +
"Machine Name : " + Environment.MachineName;
sw.WriteLine(err);
sw.WriteLine("__________________________");
sw.Flush();
sw.Close();
}
}
catch (Exception ex)
{
}
}